In a recorded conversation with FBI informant:

Farah told the informant he would kill FBI agents “if our backs are against the wall.”“Minnesota man linked to ISIS threatened to kill FBI agents, prosecutors say,” CBS News, May 22, 2015, http://www.cbsnews.com/news/minnesota-man-who-tried-to-join-isis-threatened-to-kill-fbi-agents-prosecutors-say/.